Connecting rod and internal combustion engine

Abstract

A connecting rod ( 10 ) has a big end bearing eye ( 11 ) for connection to a crankshaft, a small end bearing eye ( 12 ) for connection to a piston of a cylinder, and an eccentric adjustment device ( 13 ) for adjusting an effective connecting rod length. The eccentric adjustment device ( 13 ) has an eccentric ( 36 ) that interacts with an eccentric lever ( 14 ), and eccentric rods ( 15, 16 ) that the eccentric lever ( 14 ). The eccentric lever ( 14 ) has segments ( 38, 39 ) positioned axially in front of and behind the small end bearing eye ( 12 ). Each eccentric lever segment ( 38, 39 ) is connected to the eccentric ( 36 ) for conjoint rotation. Each eccentric lever segment ( 38, 39 ), end faces ( 43, 44 ) of the small end bearing eye ( 10 ) adjacent the respective eccentric lever segment ( 38, 39 ), and adjacent end faces ( 45, 46 ) of the eccentric ( 36 ) have a beveled contours.

What is claimed is: 
     
       1. A connecting rod, comprising a big end bearing eye for connection to a crankshaft, a small end bearing eye for connection to a piston of a cylinder, and an eccentric adjustment device for adjusting an effective connecting rod length, the eccentric adjustment device having an eccentric that interacts with an eccentric lever, and eccentric rods that engage on the eccentric lever, the eccentric lever having at least one eccentric lever segment positioned in front of and/or behind the small end bearing eye, as seen in an axial direction of the eccentric, the eccentric lever segment being connected to the eccentric for conjoint rotation, an end face of the small end bearing eye positioned adjacent to the respective eccentric lever segment and an adjacent end face of the eccentric each have a beveled contour. 
     
     
       2. The connecting rod of  claim 1 , wherein the eccentric lever has a first eccentric lever segment positioned in front of a first axial end face of the small end bearing eye and a second eccentric lever segment positioned in front of a second axial end face of the small end bearing eye, so that the small end bearing eye is between the two eccentric lever segments, wherein the two end faces of the small end bearing eye extend parallel to one another in a lower section thereof and obliquely to one another in an upper section thereof. 
     
     
       3. The connecting rod of  claim 2 , wherein the first and second eccentric lever segments are connected to the eccentric for conjoint rotation and are parallel to one another in a lower section and obliquely to one another in an upper section. 
     
     
       4. The connecting rod of  claim 3 , wherein the end faces of the eccentric extend parallel to one another in a lower section thereof and oblique to one another in an upper section thereof. 
     
     
       5. The connecting rod of  claim 4 , wherein inflection lines in the contour of the axial end faces of the eccentric and inflection lines in the contour of the eccentric lever segments extend directly adjacent to one another. 
     
     
       6. The connecting rod of  claim 3 , wherein inflection lines at which the parallel sections of the eccentric lever segments merge into the oblique sections of the eccentric lever segments lie above inflection lines at which the parallel sections of the end faces of the small end bearing eye merge into the oblique sections of the end faces of the small end bearing eye over an entire adjustment range of the eccentric lever. 
     
     
       7. The connecting rod of  claim 2 , wherein inflection lines at which the parallel sections of the end faces of the small end bearing eye merge into the oblique sections thereof are below a central point of the eccentric. 
     
     
       8. The connecting rod of  claim 7 , wherein the maximum amount by which the inflection lines in the contour of the axial end faces of the small end bearing eye lie below the central point of the eccentric is such that straight lines that extend through the central point of the eccentric and through inflection points of the inflection lines in the contour of the axial end faces of the small end bearing eye that directly adjoin the eccentric enclose an angle of at least 80°. 
     
     
       9. The connecting rod of  claim 8 , wherein inflection angles of the end faces of the small end bearing eye and inflection angles of the end faces of the eccentric correspond to one another. 
     
     
       10. The connecting rod of  claim 8 , wherein inflection angles of the end faces of the eccentric and inflection angles of the eccentric lever segments correspond to one another. 
     
     
       11. The connecting rod of  claim 8 , wherein inflection angles of the end faces of the small end bearing eye and inflection angles of the eccentric lever segments correspond to one another. 
     
     
       12. A connecting rod, comprising a big end bearing eye for connection to a crankshaft, a small end bearing eye for connection to a piston of a cylinder, and an eccentric adjustment device for adjusting an effective connecting rod length, the eccentric adjustment device having an eccentric that interacts with an eccentric lever, and eccentric rods that engage on the eccentric lever, the eccentric lever having at least one eccentric lever segment positioned in front of and/or behind the small end bearing eye, as seen in an axial direction of the eccentric, the eccentric lever segment being connected for conjoint rotation to the eccentric, and ends of the eccentric lever segment that are connected to the eccentric rods having a contour indented in a direction of the eccentric rods. 
     
     
       13. The connecting rod of  claim 12 , wherein the at least one eccentric lever segment includes a first eccentric lever segment positioned in front of a first axial end face of the small end bearing eye and a second eccentric lever segment positioned in front of a second axial end face of the small end bearing eye, so that the small end bearing eye is between the two eccentric lever segments, connecting pins connecting the ends of the eccentric lever segments to the eccentric rods, surfaces of the eccentric lever segments that face the end faces of the small end bearing eye having an indented contour, reducing the distance between the eccentric lever segments. 
     
     
       14. The connecting rod of  claim 13 , wherein indentation lines at the ends of the eccentric lever segments are configured so that when an eccentric rod engaging on ends of the eccentric lever segments has entered to the maximum extent into a hydraulic chamber, the indentation lines at this end of the eccentric lever segments extend parallel to a connecting-rod main body contour facing the respective eccentric rod. 
     
     
       15. An internal combustion engine that has an adjustable compression ratio, comprising at least one cylinder, a crankshaft, on which at least one connecting rod engages, the connecting rod having a big end bearing eye connected to the crankshaft, a small end bearing eye connected to a piston of the cylinder, and an eccentric adjustment device for adjusting an effective connecting rod length, the eccentric adjustment device having an eccentric and an eccentric lever with eccentric lever segments positioned in front of and behind the small end bearing eye and being connected to the eccentric for conjoint rotation, end faces of the small end bearing eye positioned adjacent the respective eccentric lever segments and adjacent end faces of the eccentric each having beveled contours, and eccentric rods engaging on the eccentric lever and being acted upon by hydraulic pressure prevailing in hydraulic chambers.